Your requirements could not be resolved to an installable set of packages. Problem 1 - Root composer.json requires pestphp/pest-plugin-browser ^4.1.1 -> satisfiable by pestphp/pest-plugin-browser[v4.1.1, 4.x-dev]. - pestphp/pest-plugin-browser[v4.1.1, ..., 4.x-dev] require pestphp/pest ^4.1.0 -> satisfiable by pestphp/pest[v4.1.0, ..., 4.x-dev] from composer repo (https://repo.packagist.org) but pestphp/pest dev-5cd7f3549d263e95af5f81b0d0afbf8b8802ea4e is the root package and cannot be modified. See https://getcomposer.org/dep-on-root for details and assistance.